Optimize your power transfer with the Box One Oversized Single Speed Cog, engineered for elite-level performance and durability. CNC-machined from high-strength chromoly steel, this cog features a sleek ED black finish with laser-etched graphics for a premium look that lasts.

Designed specifically for OS spline drivers—including the Onyx Ultra SS Driver—it’s compatible with both 3/32” and 1/8” chains, giving you flexibility across race setups. Available in 14T to 18T sizes, this cog delivers smooth, consistent engagement and efficient power output. Weighing as little as 20g (14T), the Box One Oversized Single Speed Cog is the perfect upgrade for serious BMX racers demanding precision, strength, and performance.

• Chromoly Steel Offers Extra Long Service Life
• 5mm Wide Inner Base to Give More Solid Interface with Freehub Body
• Oversized Spline

Material: Chromoly Steel

Process: CNC-Machined

Finish: ED Black w/Laser-Etched Graphics

Size: 14T, 15T, 16T, 17T, 18T

Compatibility:

• Driver: OS Spline*
• Chain: 3/32” or ⅛”

Weight

• 14T: 20g/0.70oz
• 15T: 28g/0.98oz
• 16T: 36g/1.27oz
• 17T: 38g/1.34oz
• 18T: 42g/1.48oz

*Onyx Ultra SS Driver

Material : 7075-T6 Aluminum

Other: Lasez-etched logos

Weight:

• 13t: 8 grams / 0.3 ounces
• 14t: 11 grams / 0.4 ounces
• 15t: 13 grams / 0.5 ounces
• 16t: 14 grams / 0.8 ounces
• 17t: 16 grams / 0.6 ounces
• 18t: 18 grams / 0.65 ounces